30 January 2019
NHP now offers remote real-time monitoring options in its earth leakage relay range with the recent addition of the RDD relay.
The RDD DIN profile earth leakage relays provide access to remote real-time monitoring with RS485 communication utilising Modbus RTU/TCP that provide instantaneous values of residual current IΔn, relay status, trip contact status, and the ability to view relay settings and the ability to program the relay.
The RDD relays supplement NHP’s existing comprehensive range of earth leakage relays, used for earth fault protection of equipment and limitation of touch voltages where automatic disconnection of supply is required, to ensure automatic disconnection within the times prescribed in the wiring rules. Harmonic filters are also now fitted as standard to prevent nuisance tripping associated with variable speed drives (VSDs).
The NHP range of earthy leakage relays are Type A (IEC 60947-2 annex B & M) with the ability to monitor circuits up to 1800A, adjustable sensitivity settings from 30mA to 30A, adjustable time delay settings of 0 – 5.0 seconds, positive and negative security options, 2P or 4P DIN or 48mm, 72mm or 96mm panel mount options, and offer reduced installation time as only two wire connections are required between the relay and toroid.
The new RS485 communication option is available in selected models, as are additional features like alarm trip changeover contact, auto reset, three-digit instantaneous digital display, test/monitoring mode with no tripping contact while commissioning and second changeover contact selectable between trip and pre-trip alarm (20, 30, 40 or 50%).
If you’re looking for the convenience of remote real-time monitoring, think NHP's earth leakage relays!